The main task of a preamplifier is to convert a weak signal into a more powerful one. To record the sound of a guitar or microphone (at home), you can purchase an audio card with a preamplifier.
Audio card with preamplifier
A sound card with a preamplifier is a high quality audio card to which you can connect a microphone with 48V phantom power. In these sound cards, the signal from the microphone is amplified by a preamplifier. Microphones with different directivity patterns are connected via a dedicated XLR connector and operate with phantom power. This jack is used to save space by allowing you to plug in your microphone, guitar, or synthesizer one at a time.
A preamplifier is an electronic amplifier that converts a weak electrical signal into a stronger one. Weak sound may come from a microphone or turntable. Usually the preamplifier is placed closer to the signal source. Thus, it can transmit the signal through the cable without significant degradation to the power amplifier.
The preamplifier is used in High-End and Hi-Fi audio systems as a hub for connecting audio system elements and amplifying voltage. On the front panel of the preamplifier there are buttons for control, and on the rear panel there are connectors for connecting various audio components, incl. guitar or microphone.
Preamp functions
There are two types of microphones: condenser and dynamic. Condenser microphones require phantom power because the supply voltage goes through the wires that carry the sound. Dynamic microphones do not need this power. Therefore, in order to use a condenser microphone, you need a sound card with a built-in microphone preamplifier, which is equipped with phantom power. You can also use a conventional sound card with line outputs, but in this case, you still need to purchase a microphone preamplifier that connects to the line inputs of the audio card.
There are also multichannel microphone amplifiers available. In addition to the amplification function, they can be equipped with a compressor or limiter function (limiting the signal level to avoid overload).
Feedback suppression can also be useful. In addition, some preamplifiers may also have a noise canceling function. If no one is speaking into the microphone, the microphone input is muted. But as soon as the signal level from the microphone exceeds a certain threshold, the microphone input will turn on again.
